This chapter focuses exclusively on medieval Jewish civilization, from the fall of the Roman Empire to about 1492. It includes alphabetically organized entries, written by scholars from around the world, include biographies, countries, events, social history, and religious concepts. Two factors made Arabic the dominant language of Jewish culture in the early medieval period, from the seventh to at least the thirteenth centuries: the Arabic conquest of the entire former Persian Empire, stretching to northern India, followed by the conquests of Asia Minor, Syria, Egypt, Palestine, North Africa, southern Italy, and Spain, and the fact that Arabic is a cognate Semitic language with some similarity to Hebrew. French was spoken by Jews not only in France but also in England. There are several "Judeo-French" glosses dating from the eleventh century, as well as numerous French words in the biblical and talmudic commentaries of "Rashi".